1. Technical Field
The present invention relates to gem-dinitro ester compounds as energetic materials and a method of preparing the same.
2. Description of the Related Art
A composite explosive has been developed in order to improve both performance and insensitivity of an explosive. Generally, a composite explosive includes a granular molecular explosive, such as a research development explosive (RDX), to provide explosiveness, and a binder composition. The binder composition is used in an amount of 2˜20 wt % based on the total amount of the composite explosive, and functions to provide dimensional stability and obtuseness to the granular molecular explosive. However, the binder composition does not have a nitro group for exhibiting explosiveness, thus deteriorating the total explosiveness thereof.
The binder composition includes a polymer and a plasticizer. In the binder composition, the content of a polymer is about three times compared to that of a plasticizer, so the characteristics of a plasticizer are very important.
In order to maximize the performance of a composite explosive, research into introducing a nitro group into a plasticizer has been widely carried out. Like this, the plasticizer, into which a nitro group is introduced, is referred to as an energetic plasticizer. Research into the energetic binder has also been widely carried out. However, typical plasticizers actually applied to explosives are formal-based or acetal-based plasticizers such as bis(2,2-dinitropropyl) formal (represented by Formula A below) or bis(2,2-dinitropropyl)acetal (represented by Formula B below).

A mixing process is needed in order to prepare a composite explosive. Generally, the mixing process is carried out at 60° C. in order to decrease the viscosity of a polymer. The molecular explosive, such as RDX, used in the composite explosive is recrystallized, and then its shape is adjusted into a polygon. However, when the shape-adjusted molecular explosive is mixed with the energized plasticizer and then the mixture is cooled to room temperature, the shape-adjusted molecular explosive is dissolved in the energetic plasticizer and then crystallized again. In this process, the molecular explosive is crystallized in various undefined shapes, such as a needle and the like, not a polygon. As such, when the shape-changed molecular explosive is included in the composite explosive, the sensitivity of the composite explosive is increased.
The sensitivity of the composite explosive attributable to the plasticizer is changed by the chemical structure of the plasticizer. That is the difference in structure between DOA and the energized plasticizer is determined according to whether or not a plasticizer includes a nitro group as an energy group. When a nitro group is introduced into a plasticizer, a molecular explosive, which is a solid filler, is dissolved in the plasticizer due to the strong polarity of the nitro group in the mixing process at 60° C., and when temperature is lowered, the molecular explosive is precipitated into a solid. During this precipitation process, the shape of the molecular explosive is changed into a sensitive shape, so that the shape-changed molecular explosive makes the composite explosive sensitive.